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/prodrive/alpr/alpr.c b/board/prodrive/alpr/alpr.c
index 1784982..a64f6b0 100644
--- a/board/prodrive/alpr/alpr.c
+++ b/board/prodrive/alpr/alpr.c
@@ -133,12 +133,13 @@
 
 int checkboard (void)
 {
-	char *s = getenv ("serial#");
+	char buf[64];
+	int i = getenv_f("serial#", buf, sizeof(buf));
 
 	printf ("Board: ALPR");
-	if (s != NULL) {
-		puts (", serial# ");
-		puts (s);
+	if (i > 0) {
+		puts(", serial# ");
+		puts(buf);
 	}
 	printf(" (Rev. %d)\n", board_rev());
 
diff --git a/board/prodrive/p3mx/p3mx.c b/board/prodrive/p3mx/p3mx.c
index 05eca52..09e4f82 100644
--- a/board/prodrive/p3mx/p3mx.c
+++ b/board/prodrive/p3mx/p3mx.c
@@ -335,13 +335,14 @@
 
 int checkboard (void)
 {
-	char *s = getenv("serial#");
+	char buf[64];
+	int i = getenv_f("serial#", buf, sizeof(buf));
 
 	printf("Board: %s", CONFIG_SYS_BOARD_NAME);
 
-	if (s != NULL) {
+	if (i > 0) {
 		puts(", serial# ");
-		puts(s);
+		puts(buf);
 	}
 	putc('\n');
 
diff --git a/board/prodrive/p3p440/p3p440.c b/board/prodrive/p3p440/p3p440.c
index 020f66d..1bb9686 100644
--- a/board/prodrive/p3p440/p3p440.c
+++ b/board/prodrive/p3p440/p3p440.c
@@ -122,12 +122,13 @@
 
 int checkboard(void)
 {
-	char *s = getenv("serial#");
+	char buf[64];
+	int i = getenv_f("serial#", buf, sizeof(buf));
 
 	printf("Board: P3P440");
-	if (s != NULL) {
+	if (i > 0) {
 		puts(", serial# ");
-		puts(s);
+		puts(buf);
 	}
 
 	if (is_monarch()) {
diff --git a/board/prodrive/pdnb3/pdnb3.c b/board/prodrive/pdnb3/pdnb3.c
index 928dd22..3aaebf2 100644
--- a/board/prodrive/pdnb3/pdnb3.c
+++ b/board/prodrive/pdnb3/pdnb3.c
@@ -101,13 +101,14 @@
  */
 int checkboard(void)
 {
-	char *s = getenv("serial#");
+	char buf[64];
+	int i = getenv_f("serial#", buf, sizeof(buf));
 
 	puts("Board: PDNB3");
 
-	if (s != NULL) {
+	if (i > 0) {
 		puts(", serial# ");
-		puts(s);
+		puts(buf);
 	}
 	putc('\n');