stdio: Fix char signedness in _load_inttype()

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

libc/stdio/_load_inttype.c

@@ -57,7 +57,7 @@ uintmax_t _load_inttype(int desttype, register const void *src, int uflag)
 		{
 			int x;
 			x = *((int *) src);
-			if (desttype == __PA_FLAG_CHAR) x = (char) x;
+			if (desttype == __PA_FLAG_CHAR) x = (signed char) x;
 #if SHRT_MAX != INT_MAX
 			if (desttype == PA_FLAG_SHORT) x = (short int) x;
 #endif