Fix GCC 4.8 compiler warnings.

hll.c:2269:13: warning: variable ‘vers’ set but not used [-Wunused-but-set-variable]
hll.c:2290:13: warning: variable ‘vers’ set but not used [-Wunused-but-set-variable]
hll.c:2311:13: warning: variable ‘vers’ set but not used [-Wunused-but-set-variable]
hll.c:2332:13: warning: variable ‘vers’ set but not used [-Wunused-but-set-variable]
hll.c:2392:13: warning: variable ‘vers’ set but not used [-Wunused-but-set-variable]
MurmurHash3.cpp:86:23: warning: always_inline function might not be inlinable [-Wattributes]
MurmurHash3.cpp:73:23: warning: always_inline function might not be inlinable [-Wattributes]
MurmurHash3.cpp:65:23: warning: always_inline function might not be inlinable [-Wattributes]
MurmurHash3.cpp:60:23: warning: always_inline function might not be inlinable [-Wattributes]