Fix parsing multiple .flags variables

strlen(flagsvar) is re-evaluated on each while-loop iteration.
As \0 string terminators are added, the loop ends prematurely,
stopping after the first introduced \0 string terminator.

Signed-off-by: Bartel Eerdekens <bartel.eerdekens@constell8.be>
Signed-off-by: Stefano Babic <sbabic@denx.de>

src/uboot_env.c

@@ -1077,9 +1077,10 @@ static int libuboot_load(struct uboot_ctx *ctx)
 #if !defined(NDEBUG)
 	fprintf(stdout, "Environment FLAGS %s\n", flagsvar);
 #endif
+		unsigned int flagslen = strlen(flagsvar);
 		pvar = flagsvar;
 
-		while (*pvar && (pvar - flagsvar) < strlen(flagsvar)) {
+		while (*pvar && (pvar - flagsvar) < flagslen) {
 			char *pnext;
 			pval = strchr(pvar, ':');
 			if (!pval)