winverbs: fix memory violation in SRQ code

winverbs: fix memory violation in SRQ code

Problem reported by Shiqing Fan:

"I got a memory violation error in wv_srq.cpp Query() function around line 202. It seems using uninitialized verbsData.output_size for memcpy. The verbsData.input_size is initialized in WvPreQueryQp (wvuverbs.cpp), and it has a similar memcpy in this function too."

wv_uverbs.cpp should initialize the output_size to 0 in all
WvPre* calls.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
git-svn-id: svn://openib.tc.cornell.edu/gen1@2848 ad392aa1-c5ef-ae45-8dd8-e69d62a5ef86