revert apache::mod::passenger default parameters for RedHat

The prior commit modified the default parameters for mod::passenger for
RedHat, hardcoding paths related to the installed package; these changes
were unnecessary and are being reverted.

The changes were originally prompted by (new) spec acceptance temps
leveraging passenger-status (to verify that passenger is running); these
tests were not working under RedHat; revisiting with the original
default parameters revealed that the RedHat tests were misconfigured
(the required PASSENGER_TMPDIR environment was not being set), so those
have been corrected.

Also, spec/class tests have be reverted to reflect the (reverted)
expected parameters.
Merge pull request #698 from jonoterc/fix_passenger_redhat

revert apache::mod::passenger default parameters for RedHat