Use 'readlink -f' instead of 'realpath'

Some distros do not ship the coreutils 'realpath', so use 'readlink -f'
instead, which is equivalent for the usage here.

Signed-off-by: Patrick McCarty <[email protected]>

Author: phmccarty

test/run.sh

@@ -8,7 +8,7 @@ testnum=0
 
 sudo rm -f *.diff *.out
 
-libdir="$(realpath "../.libs")"
+libdir="$(readlink -f "../.libs")"
 ldpath="LD_LIBRARY_PATH=$libdir"
 BSDIFF="sudo $ldpath valgrind -q $libdir/bsdiff"
 BSPATCH="sudo $ldpath valgrind -q $libdir/bspatch"