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/drivers/pci/fsl_pci_init.c b/drivers/pci/fsl_pci_init.c
index af20cf0..df76a94 100644
--- a/drivers/pci/fsl_pci_init.c
+++ b/drivers/pci/fsl_pci_init.c
@@ -390,7 +390,7 @@
 
 #ifdef CONFIG_SRIO_PCIE_BOOT_MASTER
 	/* boot from PCIE --master */
-	char *s = getenv("bootmaster");
+	char *s = env_get("bootmaster");
 	char pcie[6];
 	sprintf(pcie, "PCIE%d", pci_info->pci_num);
 
@@ -673,7 +673,7 @@
 #ifdef CONFIG_SRIO_PCIE_BOOT_MASTER
 	} else {
 		/* boot from PCIE --master releases slave's core 0 */
-		char *s = getenv("bootmaster");
+		char *s = env_get("bootmaster");
 		char pcie[6];
 		sprintf(pcie, "PCIE%d", pci_info->pci_num);
 
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 6b36c18..bbc7dab 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -427,7 +427,7 @@
 
 	if (!gd->pcidelay_done) {
 		/* wait "pcidelay" ms (if defined)... */
-		s = getenv("pcidelay");
+		s = env_get("pcidelay");
 		if (s) {
 			int val = simple_strtoul(s, NULL, 10);
 			for (i = 0; i < val; i++)
@@ -459,7 +459,7 @@
 	hose_head = NULL;
 
 	/* allow env to disable pci init/enum */
-	if (getenv("pcidisable") != NULL)
+	if (env_get("pcidisable") != NULL)
 		return;
 
 	/* now call board specific pci_init()... */
diff --git a/drivers/pci/pci_common.c b/drivers/pci/pci_common.c
index 6526de8..faf25d9 100644
--- a/drivers/pci/pci_common.c
+++ b/drivers/pci/pci_common.c
@@ -89,7 +89,7 @@
 		/*
 		 * Only skip configuration if "pciconfighost" is not set
 		 */
-		if (getenv("pciconfighost") == NULL)
+		if (env_get("pciconfighost") == NULL)
 			return 1;
 #else
 		return 1;