Unix CM: Remove redefinition of "inline"

Unix CM: Remove redefinition of "inline"

discon.h contained a redefintion of "inline" for non-gcc compilers
that's a left over from when it used "static inline", rather than
"static_inline".

Remove the redefinition, as it's now both uneccessary, and confusing.

Change-Id: I2d173385f4c3fe4b707cf86c76984b283714ced7
Reviewed-on: http://gerrit.openafs.org/4129
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>