Make some of fwrite/fclose/write/close failures visible

So that full filesystem conditions or permissions problems won't go
unnoticed.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin-fsck.c b/builtin-fsck.c
index d3f3de9..afded5e 100644
--- a/builtin-fsck.c
+++ b/builtin-fsck.c
@@ -201,12 +201,16 @@
 				char *buf = read_sha1_file(obj->sha1,
 						&type, &size);
 				if (buf) {
-					fwrite(buf, size, 1, f);
+					if (fwrite(buf, size, 1, f) != 1)
+						die("Could not write %s: %s",
+						    filename, strerror(errno));
 					free(buf);
 				}
 			} else
 				fprintf(f, "%s\n", sha1_to_hex(obj->sha1));
-			fclose(f);
+			if (fclose(f))
+				die("Could not finish %s: %s",
+				    filename, strerror(errno));
 		}
 		return;
 	}