more: cleanup gcc warnings

more: cleanup gcc warnings

Fix strict gcc warnings that come from using:
  ("-Wall -Wp,-D_FORTIFY_SOURCE=2")

more.c:185: warning: passing argument 1 of 'setupterm' discards qualifiers from pointer target type
more.c:205: warning: passing argument 1 of 'tparm' discards qualifiers from pointer target type
more.c:812: warning: pointer targets in passing argument 2 of 'mbrtowc' differ in signedness
more.c:931: warning: pointer targets in passing argument 2 of 'mbrtowc' differ in signedness
more.c:1285: warning: pointer targets in passing argument 1 of 'ttyin' differ in signedness
more.c:1486: warning: pointer targets in passing argument 1 of 'ttyin' differ in signedness
more.c:1879: warning: pointer targets in passing argument 2 of 'mbrtowc' differ in signedness

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>