Removed xxsum.c from xxHash target. (#122)
Removed xxsum.c from xxHash target. (#122)

xxsum.c is an entry point (has a main) and should not be part of
the library. This already lead to an ODR violation when running
gtest.
pierricgimmig/orbitprofiler,google/orbit,google/orbit,google/orbit,google/orbit,pierricgimmig/orbitprofiler,pierricgimmig/orbitprofiler,pierricgimmig/orbitprofiler