pkg/48544: graphics/opencv builds fails if WRKOBJDIR contains "-obj"

[tnn%nygren.pp.se@localhost]

>Number:         48544
>Category:       pkg
>Synopsis:       graphics/opencv builds fails if WRKOBJDIR contains "-obj"
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    pkg-manager
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Thu Jan 23 15:10:00 +0000 2014
>Originator:     Tobias Nygren
>Release:        
>Organization:
>Environment:
>Description:
opencv fails to build if mk.conf contains for example:
WRKOBJDIR=/tmp/pkgsrc-obj

This is due to a problematic sed script in hacks.mk.

>How-To-Repeat:

>Fix:
-SUBST_SED.opt-hack=    -e '/stereosgbm.cpp.o/s/-o/-fno-tree-pre -o/'
+SUBST_SED.opt-hack=    -e '/stereosgbm.cpp.o/s/-o /-fno-tree-pre -o /'