libcutils: abort for invalid fd

If ashmem accessors are being called with a file descriptor that
belongs to anything other than ashmem, we need to stop it right
now so that they can fix the caller.

Bug: 26871259
Change-Id: Icf9aafc3631a80b9af6fe0fea03599d61e285d21

libcutils/ashmem-dev.c

@@ -118,15 +118,16 @@ static int __ashmem_is_ashmem(int fd)
     }
 
     if (rdev) {
-        ALOGE("illegal fd=%d mode=0%o rdev=%d:%d expected 0%o %d:%d",
+        LOG_ALWAYS_FATAL("illegal fd=%d mode=0%o rdev=%d:%d expected 0%o %d:%d",
           fd, st.st_mode, major(st.st_rdev), minor(st.st_rdev),
           S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IRGRP,
           major(rdev), minor(rdev));
     } else {
-        ALOGE("illegal fd=%d mode=0%o rdev=%d:%d expected 0%o",
+        LOG_ALWAYS_FATAL("illegal fd=%d mode=0%o rdev=%d:%d expected 0%o",
           fd, st.st_mode, major(st.st_rdev), minor(st.st_rdev),
           S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IRGRP);
     }
+    /* NOTREACHED */
 
     errno = ENOTTY;
     return -1;