sysvipc.7: Rename svipc.7 to sysvipc.7

The name sysvipc is a bit more natural, and is the name used in
/proc/sysvipc.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

diff --git a/man7/svipc.7 b/man7/sysvipc.7
similarity index 100%
rename from man7/svipc.7
rename to man7/sysvipc.7