env: Rename setenv() to env_set()

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

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 fa6b485..c32f7df 100644
--- a/board/Arcturus/ucp1020/cmd_arc.c
+++ b/board/Arcturus/ucp1020/cmd_arc.c
@@ -138,7 +138,7 @@
 			printf("\t<not found>\n");
 		} else {
 			printf("\t%s\n", smac[3]);
-			setenv("SERIAL", smac[3]);
+			env_set("SERIAL", smac[3]);
 		}
 	}
 
@@ -152,7 +152,7 @@
 		char *ret = getenv("ethaddr");
 
 		if (strcmp(ret, __stringify(CONFIG_ETHADDR)) == 0) {
-			setenv("ethaddr", smac[2]);
+			env_set("ethaddr", smac[2]);
 			printf("\t%s (factory)\n", smac[2]);
 		} else {
 			printf("\t%s\n", ret);
@@ -160,8 +160,8 @@
 	}
 
 	if (strcmp(smac[1], "00:00:00:00:00:00") == 0) {
-		setenv("eth1addr", smac[2]);
-		setenv("eth2addr", smac[2]);
+		env_set("eth1addr", smac[2]);
+		env_set("eth2addr", smac[2]);
 		return 0;
 	}
 
@@ -172,7 +172,7 @@
 		char *ret = getenv("eth1addr");
 
 		if (strcmp(ret, __stringify(CONFIG_ETH1ADDR)) == 0) {
-			setenv("eth1addr", smac[1]);
+			env_set("eth1addr", smac[1]);
 			printf("\t%s (factory)\n", smac[1]);
 		} else {
 			printf("\t%s\n", ret);
@@ -180,7 +180,7 @@
 	}
 
 	if (strcmp(smac[0], "00:00:00:00:00:00") == 0) {
-		setenv("eth2addr", smac[1]);
+		env_set("eth2addr", smac[1]);
 		return 0;
 	}
 
@@ -191,7 +191,7 @@
 		char *ret = getenv("eth2addr");
 
 		if (strcmp(ret, __stringify(CONFIG_ETH2ADDR)) == 0) {
-			setenv("eth2addr", smac[0]);
+			env_set("eth2addr", smac[0]);
 			printf("\t%s (factory)\n", smac[0]);
 		} else {
 			printf("\t%s\n", ret);