Remove any trailing directory separator	from ld_canon_sysroot and adjust ld_canon_sysroot_len.
    
    The problem was the ld expect libiberty/lrealpath() to always return a
    path, but in some cases it returns a prefix. It seemed like too much of
    an earthquake to propose a fix to lrealpath.
    
    	* ldmain.c (main): Remove directory separator, if any, from the
    	end of the canonicalized sysroot.