p uninitialized in mice.c at 1843

[barzog]

gpm-mice.c.diff.txt During compilation on gentoo we see following:

• QA Notice: Package triggers severe warnings which indicate that it

•        may exhibit random runtime failures.
  

• mice.c:1843:10: warning: ‘p’ is used uninitialized in this function [-Wuninitialized]

simple fix for that is attached