kconfig: add xrealloc() helper

We already have xmalloc(), xcalloc().  Add xrealloc() as well
to save tedious error handling.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

scripts/kconfig/nconf.gui.c

@@ -6,6 +6,7 @@
  *
  */
 #include "nconf.h"
+#include "lkc.h"
 
 /* a list of all the different widgets we use */
 attributes_t attributes[ATTR_MAX+1] = {0};
@@ -374,7 +375,7 @@ int dialog_inputbox(WINDOW *main_window,
 
 	if (strlen(init)+1 > *result_len) {
 		*result_len = strlen(init)+1;
-		*resultp = result = realloc(result, *result_len);
+		*resultp = result = xrealloc(result, *result_len);
 	}
 
 	/* find the widest line of msg: */