[MTHCA] Fix off-by-one in FMR handling on memfree (mlnx: 2957)

[MTHCA] Fix off-by-one in FMR handling on memfree (mlnx: 2957)
(Linux, 05/01/07, Michael S. Tsirkin, commit: 46707e96b7254663139225ab6c9ab9922cd8c435)

mthca_table_find() will return the wrong address when the table entry
being searched for is exactly at the beginning of a sglist entry
(other than the first), because it uses >= when it should use >.

Example: assume we have 2 entries in scatterlist, 4K each, offset is
4K.  The current code will return first entry + 4K when we really want
the second entry.

In particular this means mapping an FMR on a memfree HCA may end up
writing the page table into the wrong place, leading to memory
corruption and also causing the HCA to use an incorrect address
translation table.

git-svn-id: svn://openib.tc.cornell.edu/gen1/trunk@1507 ad392aa1-c5ef-ae45-8dd8-e69d62a5ef86