Fix #186: ICASE type mismatch in beam_shower
Fix #186: ICASE type mismatch in beam_shower

Update ICASE variable type to $LONG_INT in subroutine beam_shower. This
local instance of ICASE was neglected when updating the type of ICASE in
the main routine, causing a compiler warning.
marenaud/EGSnrc,mchamberland/EGSnrc,crcrewso/EGSnrc,MartinMartinov/EGSnrc,MartinMartinov/EGSnrc,ftessier/EGSnrc,nrc-cnrc/EGSnrc,ftessier/EGSnrc,crcrewso/EGSnrc,MartinMartinov/EGSnrc,crcrewso/EGSnrc,marenaud/EGSnrc,ftessier/EGSnrc,crcrewso/EGSnrc,MartinMartinov/EGSnrc,ftessier/EGSnrc,marenaud/EGSnrc,nrc-cnrc/EGSnrc,nrc-cnrc/EGSnrc,mchamberland/EGSnrc,marenaud/EGSnrc,mchamberland/EGSnrc,ftessier/EGSnrc,marenaud/EGSnrc,MartinMartinov/EGSnrc,mchamberland/EGSnrc,mchamberland/EGSnrc,crcrewso/EGSnrc,mchamberland/EGSnrc,marenaud/EGSnrc,nrc-cnrc/EGSnrc,nrc-cnrc/EGSnrc,ftessier/EGSnrc