fixed a klocwork issue

BZ: 185618

In the function stream_memcpy, if the size isn't aligned to 16, it use memcpy.
The function should end itself after calling memcpy.

Change-Id: Idae5888ca54692b74cb98da774e6ae984d38c6df
Signed-off-by: Sun, Jian <jianx.sun@intel.com>
diff --git a/videodecoder/use_util_sse4.h b/videodecoder/use_util_sse4.h
index 073ae22..338622c 100644
--- a/videodecoder/use_util_sse4.h
+++ b/videodecoder/use_util_sse4.h
@@ -34,6 +34,7 @@
     bool isAligned = (((size_t)(src_buff) | (size_t)(dst_buff)) & 0xF) == 0;
     if (!isAligned) {
         memcpy(dst_buff, src_buff, size);
+        return;
     }
 
     static const size_t regs_count = 8;