redhat/Makefile: Drop quotation marks around string definitions

dzickus reports that 'make dist-srpm-gcov' doesn't work anymore. Not only
is an error reported,

error: line 555: Illegal char '"' (0x22) in: Release: 0.rc7.53".gcov".fc35  
error: query of specfile /home/prarit/git-kernel/kernel-ark/redhat/rpm/SOURCES/kernel.spec failed, can't parse  

but the resulting specfile does not contain '%define _with_gcov 1'.

Exporting the Makefile variables into the scripts results in quotation
marks now being interpreted as part of the string. As can be seen in the
error above the quotation mark is the problem.

Drop quotation marks around string definitions.

Reported-by: Don Zickus dzickus@redhat.com
Signed-off-by: Prarit Bhargava prarit@redhat.com