display: remove compiler warnings

Use correct typecasts and format specifiers and resolve
compiler warnings

Change-Id: I51b12ecb78a9a496cf1f76c3d32892a203f70c43
diff --git a/libgralloc/gralloc_priv.h b/libgralloc/gralloc_priv.h
index 7a4fc15..ce33cea 100644
--- a/libgralloc/gralloc_priv.h
+++ b/libgralloc/gralloc_priv.h
@@ -259,7 +259,7 @@
                 hnd->magic != sMagic)
             {
                 ALOGD("Invalid gralloc handle (at %p): "
-                      "ver(%d/%u) ints(%d/%d) fds(%d/%d)"
+                      "ver(%d/%zu) ints(%d/%d) fds(%d/%d)"
                       "magic(%c%c%c%c/%c%c%c%c)",
                       h,
                       h ? h->version : -1, sizeof(native_handle),