common/cmd_bootm.c: fix subcommand processing in OS specific do_bootm_xxx() functions

In commit "5c427e4: use BOOTM_STATE_OS_CMDLINE flag for plain bootm"
and "3d187b3: Only pass BOOTM_STATE_OS_CMDLINE on PowerPC/MIPS",
BOOTM_STATE_OS_CMDLINE was added to do_bootm for PowerPC and MIPS. This
breaks other OSes (vxworks, netbsd, plan9,...) that don't support
subcommand processing, e.g. they all contain the following code in their
do_bootm_xxx():

    if (flag & BOOTM_STATE_OS_PREP)
            return 0;
    if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
            return 1;

which will result a "subcommand not supported" error.
This patch changes the above logic to:

    /* if not go command, pretend everything to be OK */
    if (flag != BOOTM_STATE_OS_GO)
         return 0;

Signed-off-by: Miao Yan <miao.yan@windriver.com>
diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
index 166b901..ba73f57 100644
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -1469,10 +1469,8 @@
 	char *consdev;
 	char *cmdline;
 
-	if (flag & BOOTM_STATE_OS_PREP)
+	if (flag != BOOTM_STATE_OS_GO)
 		return 0;
-	if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
-		return 1;
 
 #if defined(CONFIG_FIT)
 	if (!images->legacy_hdr_valid) {
@@ -1550,10 +1548,8 @@
 {
 	image_header_t *hdr = &images->legacy_hdr_os_copy;
 
-	if (flag & BOOTM_STATE_OS_PREP)
+	if (flag != BOOTM_STATE_OS_GO)
 		return 0;
-	if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
-		return 1;
 
 #if defined(CONFIG_FIT)
 	if (!images->legacy_hdr_valid) {
@@ -1574,10 +1570,8 @@
 {
 	void (*entry_point)(bd_t *);
 
-	if (flag & BOOTM_STATE_OS_PREP)
+	if (flag != BOOTM_STATE_OS_GO)
 		return 0;
-	if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
-		return 1;
 
 #if defined(CONFIG_FIT)
 	if (!images->legacy_hdr_valid) {
@@ -1609,10 +1603,8 @@
 {
 	void (*entry_point)(void);
 
-	if (flag & BOOTM_STATE_OS_PREP)
+	if (flag != BOOTM_STATE_OS_GO)
 		return 0;
-	if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
-		return 1;
 
 #if defined(CONFIG_FIT)
 	if (!images->legacy_hdr_valid) {
@@ -1645,10 +1637,8 @@
 	void (*entry_point)(void);
 	char *s;
 
-	if (flag & BOOTM_STATE_OS_PREP)
+	if (flag != BOOTM_STATE_OS_GO)
 		return 0;
-	if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
-		return 1;
 
 #if defined(CONFIG_FIT)
 	if (!images->legacy_hdr_valid) {
@@ -1694,10 +1684,8 @@
 {
 	char str[80];
 
-	if (flag & BOOTM_STATE_OS_PREP)
+	if (flag != BOOTM_STATE_OS_GO)
 		return 0;
-	if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
-		return 1;
 
 #if defined(CONFIG_FIT)
 	if (!images->legacy_hdr_valid) {
@@ -1719,10 +1707,8 @@
 	char *local_args[2];
 	char str[16];
 
-	if (flag & BOOTM_STATE_OS_PREP)
+	if (flag != BOOTM_STATE_OS_GO)
 		return 0;
-	if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
-		return 1;
 
 #if defined(CONFIG_FIT)
 	if (!images->legacy_hdr_valid) {
@@ -1746,10 +1732,8 @@
 {
 	void (*entry_point)(void);
 
-	if (flag & BOOTM_STATE_OS_PREP)
+	if (flag != BOOTM_STATE_OS_GO)
 		return 0;
-	if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
-		return 1;
 
 #if defined(CONFIG_FIT)
 	if (!images->legacy_hdr_valid) {