only do uncryption on packages in /data

If recovery is invoked with a package somewhere other than /data,
leave it alone.

Change-Id: Ief358b53df467ae24a65e30e7a631da59bf13683
diff --git a/uncrypt/uncrypt.c b/uncrypt/uncrypt.c
index 24d1ffc..bce53db 100644
--- a/uncrypt/uncrypt.c
+++ b/uncrypt/uncrypt.c
@@ -159,7 +159,7 @@
 
     while (fgets(temp, sizeof(temp), f)) {
         printf("read: %s", temp);
-        if (strncmp(temp, "--update_package=", strlen("--update_package=")) == 0) {
+        if (strncmp(temp, "--update_package=/data/", strlen("--update_package=/data/")) == 0) {
             fn = strdup(temp + strlen("--update_package="));
             strcpy(temp, "--update_package=@" CACHE_BLOCK_MAP "\n");
         }