common: cli_hush: avoid memory leak

Need to free memory avoid memory leak, when error.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@konsulko.com>
diff --git a/common/cli_hush.c b/common/cli_hush.c
index f075459..7f69c06 100644
--- a/common/cli_hush.c
+++ b/common/cli_hush.c
@@ -2471,11 +2471,16 @@
 		}
 		argc = ++child->argc;
 		child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
-		if (child->argv == NULL) return 1;
+		if (child->argv == NULL) {
+			free(str);
+			return 1;
+		}
 		child->argv_nonnull = realloc(child->argv_nonnull,
 					(argc+1)*sizeof(*child->argv_nonnull));
-		if (child->argv_nonnull == NULL)
+		if (child->argv_nonnull == NULL) {
+			free(str);
 			return 1;
+		}
 		child->argv[argc-1]=str;
 		child->argv_nonnull[argc-1] = dest->nonnull;
 		child->argv[argc]=NULL;