fix warnings when building openssl with (gcc 3.3.1):

-Wmissing-prototypes -Wcomment -Wformat -Wimplicit -Wmain -Wmultichar
-Wswitch -Wshadow -Wtrigraphs -Werror -Wchar-subscripts
-Wstrict-prototypes -Wreturn-type -Wpointer-arith  -W -Wunused
-Wno-unused-parameter -Wuninitialized