ash: redir: Fix typo in noclobber code

Upstream commit "redir: Fix typo in noclobber code"

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash.c b/shell/ash.c
index 70a278f..35ea58f 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -5391,7 +5391,7 @@
 				f = open(fname, O_WRONLY, 0666);
 				if (f < 0)
 					goto ecreate;
-				if (fstat(f, &sb) < 0 && S_ISREG(sb.st_mode)) {
+				if (!fstat(f, &sb) && S_ISREG(sb.st_mode)) {
 					close(f);
 					errno = EEXIST;
 					goto ecreate;