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/Arcturus/ucp1020/cmd_arc.c b/board/Arcturus/ucp1020/cmd_arc.c
index c32f7df..0d3ac88 100644
--- a/board/Arcturus/ucp1020/cmd_arc.c
+++ b/board/Arcturus/ucp1020/cmd_arc.c
@@ -149,7 +149,7 @@
 	if (smac[2][0] == 0xFF) {
 		printf("\t<not found>\n");
 	} else {
-		char *ret = getenv("ethaddr");
+		char *ret = env_get("ethaddr");
 
 		if (strcmp(ret, __stringify(CONFIG_ETHADDR)) == 0) {
 			env_set("ethaddr", smac[2]);
@@ -169,7 +169,7 @@
 	if (smac[1][0] == 0xFF) {
 		printf("\t<not found>\n");
 	} else {
-		char *ret = getenv("eth1addr");
+		char *ret = env_get("eth1addr");
 
 		if (strcmp(ret, __stringify(CONFIG_ETH1ADDR)) == 0) {
 			env_set("eth1addr", smac[1]);
@@ -188,7 +188,7 @@
 	if (smac[0][0] == 0xFF) {
 		printf("\t<not found>\n");
 	} else {
-		char *ret = getenv("eth2addr");
+		char *ret = env_get("eth2addr");
 
 		if (strcmp(ret, __stringify(CONFIG_ETH2ADDR)) == 0) {
 			env_set("eth2addr", smac[0]);
diff --git a/board/Arcturus/ucp1020/ucp1020.c b/board/Arcturus/ucp1020/ucp1020.c
index 2cc2e54..dfdaf04 100644
--- a/board/Arcturus/ucp1020/ucp1020.c
+++ b/board/Arcturus/ucp1020/ucp1020.c
@@ -64,7 +64,7 @@
 
 	for (i = 0; i < GPIO_MAX_NUM; i++) {
 		sprintf(envname, "GPIO%d", i);
-		val = getenv(envname);
+		val = env_get(envname);
 		if (val) {
 			char direction = toupper(val[0]);
 			char level = toupper(val[1]);
@@ -82,7 +82,7 @@
 		}
 	}
 
-	val = getenv("PCIE_OFF");
+	val = env_get("PCIE_OFF");
 	if (val) {
 		gpio_direction_input(GPIO_PCIE1_EN);
 		gpio_direction_input(GPIO_PCIE2_EN);
@@ -91,7 +91,7 @@
 		gpio_direction_output(GPIO_PCIE2_EN, 1);
 	}
 
-	val = getenv("SDHC_CDWP_OFF");
+	val = env_get("SDHC_CDWP_OFF");
 	if (!val) {
 		ccsr_gur_t *gur = (void *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
 
@@ -214,7 +214,7 @@
 	else
 		printf("NCT72(0x%x): ready\n", id2);
 
-	kval = getenv("kernelargs");
+	kval = env_get("kernelargs");
 
 	mmc = find_mmc_device(0);
 	if (mmc)
@@ -238,7 +238,7 @@
 	get_arc_info();
 
 	if (kval) {
-		sval = getenv("SERIAL");
+		sval = env_get("SERIAL");
 		if (sval) {
 			strcpy(newkernelargs, "SN=");
 			strcat(newkernelargs, sval);