Build: remove redundant -rpath

LDSHFLAGS specifies -rpath, but is only used when LDFLAGS are specified,
and LDFLAGS also set the same -rpath.  Remove the redundant definition
in LDSHFLAGS.

Makefile

@@ -12,7 +12,7 @@ AR	    ?= ar
 ARFLAGS = rcv
 
 SHLD = ${CC} ${CFLAGS}
-LDSHFLAGS = -shared -Wl,-Bsymbolic  -Wl,-rpath -Wl,/usr/lib -Wl,-rpath,/usr/lib
+LDSHFLAGS = -shared -Wl,-Bsymbolic
 LDFLAGS += -Wl,-rpath -Wl,/usr/lib -Wl,-rpath,/usr/lib
 
 # Set RANLIB to ranlib on systems that require it (Sun OS < 4, Mac OSX)