gzip: flush output buffer after stored blocks only if necessary

function                                             old     new   delta
flush_block                                          671     680      +9

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

archival/gzip.c

@@ -634,6 +634,7 @@ static void copy_block(char *buf, unsigned len, int header)
 		put_8bit(*buf++);
 	}
 	/* The above can 32-bit misalign outbuf */
+	if (G1.outcnt & 3) /* syscalls are expensive, is it really misaligned? */
 		flush_outbuf_if_32bit_optimized();
 }