env: Rename getenv/_f() to env_get()

We are now using an env_ prefix for environment functions. Rename these
two functions for consistency. Also add function comments in common.h.

Quite a few places use getenv() in a condition context, provoking a
warning from checkpatch. These are fixed up in this patch also.

Suggested-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/keymile/common/common.c b/board/keymile/common/common.c
index 56d3044..6cd2812 100644
--- a/board/keymile/common/common.c
+++ b/board/keymile/common/common.c
@@ -54,7 +54,7 @@
 	env_set("pnvramaddr", (char *)buf);
 
 	/* try to read rootfssize (ram image) from environment */
-	p = getenv("rootfssize");
+	p = env_get("rootfssize");
 	if (p != NULL)
 		strict_strtoul(p, 16, &rootfssize);
 	pram = (rootfssize + CONFIG_KM_RESERVED_PRAM + CONFIG_KM_PHRAM +
@@ -236,10 +236,10 @@
 	}
 
 	/* now try to read values from environment if available */
-	p = getenv("boardid");
+	p = env_get("boardid");
 	if (p != NULL)
 		rc = strict_strtoul(p, 16, &envbid);
-	p = getenv("hwkey");
+	p = env_get("hwkey");
 	if (p != NULL)
 		rc = strict_strtoul(p, 16, &envhwkey);
 
@@ -253,7 +253,7 @@
 		 * BoardId/HWkey not available in the environment, so try the
 		 * environment variable for BoardId/HWkey list
 		 */
-		char *bidhwklist = getenv("boardIdListHex");
+		char *bidhwklist = env_get("boardIdListHex");
 
 		if (bidhwklist) {
 			int found = 0;
@@ -355,7 +355,7 @@
 #if defined(CONFIG_POST)
 	testpin = post_hotkeys_pressed();
 #endif
-	s = getenv("test_bank");
+	s = env_get("test_bank");
 	/* when test_bank is not set, act as if testpin is not asserted */
 	testboot = (testpin != 0) && (s);
 	if (verbose) {
diff --git a/board/keymile/common/ivm.c b/board/keymile/common/ivm.c
index dc40a83..f1321d9 100644
--- a/board/keymile/common/ivm.c
+++ b/board/keymile/common/ivm.c
@@ -261,7 +261,7 @@
 
 	GET_STRING("IVM_Symbol", IVM_POS_SYMBOL_ONLY, 8)
 	GET_STRING("IVM_DeviceName", IVM_POS_SHORT_TEXT, 64)
-	tmp = (unsigned char *) getenv("IVM_DeviceName");
+	tmp = (unsigned char *)env_get("IVM_DeviceName");
 	if (tmp) {
 		int	len = strlen((char *)tmp);
 		int	i = 0;
diff --git a/board/keymile/km_arm/km_arm.c b/board/keymile/km_arm/km_arm.c
index 08ae9ae..af1ebc4 100644
--- a/board/keymile/km_arm/km_arm.c
+++ b/board/keymile/km_arm/km_arm.c
@@ -201,7 +201,7 @@
 #if defined(CONFIG_KM_MGCOGE3UN)
 	char *wait_for_ne;
 	u8 dip_switch = kw_gpio_get_value(KM_FLASH_ERASE_ENABLE);
-	wait_for_ne = getenv("waitforne");
+	wait_for_ne = env_get("waitforne");
 
 	if ((wait_for_ne != NULL) && (dip_switch == 0)) {
 		if (strcmp(wait_for_ne, "true") == 0) {
diff --git a/board/keymile/kmp204x/kmp204x.c b/board/keymile/kmp204x/kmp204x.c
index 095e467..671bddf 100644
--- a/board/keymile/kmp204x/kmp204x.c
+++ b/board/keymile/kmp204x/kmp204x.c
@@ -239,7 +239,7 @@
 	unsigned char mac_addr[6];
 
 	/* get the mac addr from env */
-	tmp = getenv("ethaddr");
+	tmp = env_get("ethaddr");
 	if (!tmp) {
 		printf("ethaddr env variable not defined\n");
 		return;