Correction to TRACE format strings

When built with "#define FUSE_TRACE 1" numerous TRACE statements
failed to compile because of mismatches between format strings and
types (uint64_t and size_t). These have been corrected by using the
format strings from the inttype.h header file, or %zu.

Change-Id: I36cd6f8da0790f1218d7dbaaa5b3bbfa4df7fdee
Signed-off-by: Marcus Oakland <marcus.oakland@arm.com>