Fix NaNs in pegs4 compiled without -ffast-math
Fix NaNs in pegs4 compiled without -ffast-math

Switch the order of mathematical operations to obtain the right result
with or without the -ffast-math compiler flag. Previously, without the
-ffast-math compiler flag, the RLC variable evaluated to 0 and pegs4
would output NaN data.

MartinMartinov/EGSnrc,MartinMartinov/EGSnrc,ftessier/EGSnrc,crcrewso/EGSnrc,ftessier/EGSnrc,nrc-cnrc/EGSnrc,crcrewso/EGSnrc,crcrewso/EGSnrc,mchamberland/EGSnrc,nrc-cnrc/EGSnrc,mchamberland/EGSnrc,ftessier/EGSnrc,marenaud/EGSnrc,marenaud/EGSnrc,MartinMartinov/EGSnrc,mchamberland/EGSnrc,nrc-cnrc/EGSnrc,MartinMartinov/EGSnrc,ftessier/EGSnrc,ftessier/EGSnrc,marenaud/EGSnrc,nrc-cnrc/EGSnrc,marenaud/EGSnrc,marenaud/EGSnrc,MartinMartinov/EGSnrc,nrc-cnrc/EGSnrc,ftessier/EGSnrc,crcrewso/EGSnrc,mchamberland/EGSnrc,mchamberland/EGSnrc,marenaud/EGSnrc,mchamberland/EGSnrc,crcrewso/EGSnrc