Fix problem with "make -C /usr/ports/ search name=text"

[rum1cro_yandex.ru]

Summary

https://lists.freebsd.org/pipermail/freebsd-current/2017-November/067386.html
[tiger at laptop]:/>make -C /usr/ports/ search name=teeworlds display=name,path,info
[tiger at laptop]:/>
but
[tiger at laptop]:/>cd /usr/ports/
[tiger at laptop]:/usr/ports>make search name=teeworlds display=name,path,info
Port: teeworlds-0.6.4_4
Path: /usr/ports/games/teeworlds
Info: Platform game featuring buggers equipped with weapons

Test Plan

Should work:
make -C /usr/ports/ search name=teeworlds

[bdrewery]

[/usr/src] # make -C bin/sh/ -V .CURDIR
/usr/src/bin/sh
[/usr/src] # fmake -C bin/sh/ -V .CURDIR
/usr/src/bin/sh
[/usr/src] # fmake -C bin/sh//// -V .CURDIR
/usr/src/bin/sh
[/usr/src] # bmake -C bin/sh//// -V .CURDIR
/usr/src/bin/sh

I can't seem to find any .CURDIR case that isn't right regarding ///.

[/tmp/src/bin/sh] # make -V .CURDIR
/usr/src/bin/sh
[/tmp/src/bin/sh] # cd /tmp/src/bin/sh////
[/tmp/src/bin/sh] # make -V .CURDIR
/usr/src/bin/sh
[/tmp/src/bin/sh] # bmake -V .CURDIR
/tmp/src/bin/sh

Aha here is a bad case through a symlink with a really old bmake...

[/tmp/src/bin/sh] # bmake -V MAKE_VERSION
20141111

The bmake in head doesn't have the problem.

~/git/freebsd3/bin/sh # make -V .CURDIR
/root/git/freebsd2/bin/sh
~/git/freebsd3/bin/sh # make -V MAKE_VERSION
20170720