lzop: add overflow check

See CVE-2014-4607
http://www.openwall.com/lists/oss-security/2014/06/26/20

function                                             old     new   delta
lzo1x_decompress_safe                               1010    1031     +21

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/archival/libarchive/lzo1x_d.c b/archival/libarchive/lzo1x_d.c
index 9bc1270..40b167e 100644
--- a/archival/libarchive/lzo1x_d.c
+++ b/archival/libarchive/lzo1x_d.c
@@ -92,6 +92,7 @@
 				ip++;
 				NEED_IP(1);
 			}
+			TEST_IV(t);
 			t += 15 + *ip++;
 		}
 		/* copy literals */
@@ -224,6 +225,7 @@
 						ip++;
 						NEED_IP(1);
 					}
+					TEST_IV(t);
 					t += 31 + *ip++;
 				}
 #if defined(COPY_DICT)
@@ -265,6 +267,7 @@
 						ip++;
 						NEED_IP(1);
 					}
+					TEST_IV(t);
 					t += 7 + *ip++;
 				}
 #if defined(COPY_DICT)