make: Make protobuf target to depend on *.ch
make: Make protobuf target to depend on *.ch

Our general source code depends on headers
generated during protobuf library building
but if library is already built and *.ch
files are removed we might hit a problem
where dep files can't be generated.

Thus add explicit rule pointing out that
library depends on generated *.ch files.

Signed-off-by: Cyrill Gorcunov <7a1ea01eee6961eb1e372e3508c2670446d086f4@openvz.org>
Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@parallels.com>

LK4D4/criu,wtf42/criu,wtf42/criu,biddyweb/criu,tych0/criu,marcosnils/criu,efiop/criu,svloyso/criu,AuthenticEshkinKot/criu,ldu4/criu,gablg1/criu,marcosnils/criu,svloyso/criu,rentzsch/criu,ldu4/criu,KKoukiou/criu-remote,eabatalov/criu,rentzsch/criu,sdgdsffdsfff/criu,fbocharov/criu,efiop/criu,KKoukiou/criu-remote,eabatalov/criu,eabatalov/criu,marcosnils/criu,tych0/criu,gablg1/criu,wtf42/criu,gonkulator/criu,gonkulator/criu,LK4D4/criu,gablg1/criu,efiop/criu,wtf42/criu,LK4D4/criu,KKoukiou/criu-remote,wtf42/criu,efiop/criu,gonkulator/criu,efiop/criu,svloyso/criu,AuthenticEshkinKot/criu,svloyso/criu,biddyweb/criu,ldu4/criu,biddyweb/criu,ldu4/criu,AuthenticEshkinKot/criu,wtf42/criu,marcosnils/criu,LK4D4/criu,sdgdsffdsfff/criu,marcosnils/criu,gablg1/criu,rentzsch/criu,sdgdsffdsfff/criu,tych0/criu,rentzsch/criu,tych0/criu,gonkulator/criu,rentzsch/criu,fbocharov/criu,tych0/criu,gonkulator/criu,eabatalov/criu,sdgdsffdsfff/criu,kawamuray/criu,KKoukiou/criu-remote,gonkulator/criu,marcosnils/criu,AuthenticEshkinKot/criu,eabatalov/criu,biddyweb/criu,tych0/criu,sdgdsffdsfff/criu,biddyweb/criu,fbocharov/criu,AuthenticEshkinKot/criu,AuthenticEshkinKot/criu,biddyweb/criu,fbocharov/criu,kawamuray/criu,kawamuray/criu,rentzsch/criu,fbocharov/criu,efiop/criu,svloyso/criu,kawamuray/criu,kawamuray/criu,KKoukiou/criu-remote,fbocharov/criu,ldu4/criu,ldu4/criu,kawamuray/criu,gablg1/criu,LK4D4/criu,LK4D4/criu,gablg1/criu,eabatalov/criu,sdgdsffdsfff/criu,svloyso/criu,KKoukiou/criu-remote