Fix incorrect use of getenv() before relocation

A large number of boards incorrectly used getenv() in their board init
code running before relocation.  In some cases this caused U-Boot to
hang when certain environment variables grew too long.
Fix the code to use getenv_r().

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Stefan Roese <sr@denx.de>
Cc: The LEOX team <team@leox.org>
Cc: Michael Schwingen <michael@schwingen.org>
Cc: Georg Schardt <schardt@team-ctech.de>
Cc: Werner Pfister <Pfister_Werner@intercontrol.de>
Cc: Dirk Eibach <eibach@gdsys.de>
Cc: Peter De Schrijver <p2@mind.be>
Cc: John Zhan <zhanz@sinovee.com>
Cc: Rishi Bhattacharya <rishi@ti.com>
Cc: Peter Tyser <ptyser@xes-inc.com>
diff --git a/board/xes/common/board.c b/board/xes/common/board.c
index 738f0a6..4e60bb5 100644
--- a/board/xes/common/board.c
+++ b/board/xes/common/board.c
@@ -13,7 +13,9 @@
 int checkboard(void)
 {
 	char name[] = CONFIG_SYS_BOARD_NAME;
+	char buf[64];
 	char *s;
+	int i;
 
 #ifdef CONFIG_SYS_FORM_CUSTOM
 	s = "Custom";
@@ -52,12 +54,15 @@
 
 	/* Display board specific information */
 	puts("       ");
-	if ((s = getenv("board_rev")))
-		printf("Rev %s, ", s);
-	if ((s = getenv("serial#")))
-		printf("Serial# %s, ", s);
-	if ((s = getenv("board_cfg")))
-		printf("Cfg %s", s);
+	i = getenv_f("board_rev", buf, sizeof(buf));
+	if (i > 0)
+		printf("Rev %s, ", buf);
+	i = getenv_f("serial#", buf, sizeof(buf));
+	if (i > 0)
+		printf("Serial# %s, ", buf);
+	i = getenv_f("board_cfg", buf, sizeof(buf));
+	if (i > 0)
+		printf("Cfg %s", buf);
 	puts("\n");
 
 	return 0;