Revert "run-command: prettify -D_FORTIFY_SOURCE workaround"

This reverts commit ebec842, which
somehow mistakenly thought that any non-zero return from write(2) is
an error.

Author: gitster

run-command.c

@@ -67,26 +67,21 @@ static int child_notifier = -1;
 
 static void notify_parent(void)
 {
-	/*
-	 * execvp failed.  If possible, we'd like to let start_command
-	 * know, so failures like ENOENT can be handled right away; but
-	 * otherwise, finish_command will still report the error.
-	 */
-	if (write(child_notifier, "", 1))
-		; /* yes, dear gcc -D_FORTIFY_SOURCE, there was an error. */
+	ssize_t unused;
+	unused = write(child_notifier, "", 1);
 }
 
 static NORETURN void die_child(const char *err, va_list params)
 {
 	char msg[4096];
+	ssize_t unused;
 	int len = vsnprintf(msg, sizeof(msg), err, params);
 	if (len > sizeof(msg))
 		len = sizeof(msg);
 
-	if (write(child_err, "fatal: ", 7) ||
-	    write(child_err, msg, len) ||
-	    write(child_err, "\n", 1))
-		; /* yes, gcc -D_FORTIFY_SOURCE, we know there was an error. */
+	unused = write(child_err, "fatal: ", 7);
+	unused = write(child_err, msg, len);
+	unused = write(child_err, "\n", 1);
 	exit(128);
 }
 #endif