Fix bugprone-posix-return warnings

Test: WITH_TIDY=1 make
Bug: 154629561
Change-Id: I27b3ffc430400b4f133890748a2124afdabb7814
diff --git a/media/mtp/MtpFfsHandle.cpp b/media/mtp/MtpFfsHandle.cpp
index bd6a6c6..c8b4a03 100644
--- a/media/mtp/MtpFfsHandle.cpp
+++ b/media/mtp/MtpFfsHandle.cpp
@@ -114,11 +114,11 @@
 void MtpFfsHandle::advise(int fd) {
     for (unsigned i = 0; i < NUM_IO_BUFS; i++) {
         if (posix_madvise(mIobuf[i].bufs.data(), MAX_FILE_CHUNK_SIZE,
-                POSIX_MADV_SEQUENTIAL | POSIX_MADV_WILLNEED) < 0)
+                POSIX_MADV_SEQUENTIAL | POSIX_MADV_WILLNEED) != 0)
             PLOG(ERROR) << "Failed to madvise";
     }
     if (posix_fadvise(fd, 0, 0,
-                POSIX_FADV_SEQUENTIAL | POSIX_FADV_NOREUSE | POSIX_FADV_WILLNEED) < 0)
+                POSIX_FADV_SEQUENTIAL | POSIX_FADV_NOREUSE | POSIX_FADV_WILLNEED) != 0)
         PLOG(ERROR) << "Failed to fadvise";
 }