Prefer SRCTOP paths for bits we're grabbing from libc.

Sponsored by: Netflix

sys/boot/geli/Makefile

@@ -21,7 +21,7 @@ CFLAGS+=        -m32
 WARNS?=		0
 
 # string functions from libc
-.PATH: ${.CURDIR}/../../../lib/libc/string
+.PATH: ${SRCTOP}/lib/libc/string
 SRCS+=  bcmp.c bcopy.c bzero.c
 
 # Our password input method

sys/boot/powerpc/boot1.chrp/Makefile

@@ -19,7 +19,7 @@ LDFLAGS=-nostdlib -static -Wl,-N
 
 .include "../Makefile.inc"
 
-.PATH:  ${.CURDIR}/../../../libkern ${.CURDIR}/../../../../lib/libc/powerpc/gen ${.CURDIR}
+.PATH:  ${.CURDIR}/../../../libkern ${SRCTOP}/lib/libc/powerpc/gen ${.CURDIR}
 
 # The following inserts out objects into a template HFS 
 # created by generate-hfs.sh