make rebuild required when building on a 5.1 system

Hi, when building on a 5.1 system

It appears that make should be rebuild before doing a make build of RELENG_5_2
when running the security branch RELENG_5_1. This should be added to UPDATING:

"/usr/src/Makefile.inc1", line 745: warning: String comparison operator should be either == or !=
"/usr/src/Makefile.inc1", line 745: Malformed conditional ((!defined(NO_RESCUE) ||  defined(RELEASEDIR)) &&  (${TARGET_ARCH} != ${MACHINE_ARCH} || ${BOOTSTRAPPING} < 501101))
"/usr/src/Makefile.inc1", line 745: Missing dependency operator
"/usr/src/Makefile.inc1", line 747: if-less endif
"/usr/src/Makefile.inc1", line 747: Need an operator
make.old: fatal errors encountered -- cannot continue
*** Error code 1

Stop in /usr/src.


After doing:

	cd /usr/src/usr.bin/make
	make obj && make depend && make && make install

the error disappeared


Thanks,

martijn