Don't use -S git in autosetup as it requires git in a buildroot

Fixes:

+ '[' 0 -ne 0 ']'
+ cd libsepol-2.5
+ /usr/bin/chmod -Rf a+rX,u+w,g-w,o-w .
+ /usr/bin/git init -q
/var/tmp/rpm-tmp.yCRSdD: line 42: /usr/bin/git: No such file or directory
error: Bad exit status from /var/tmp/rpm-tmp.yCRSdD (%prep)
    Bad exit status from /var/tmp/rpm-tmp.yCRSdD (%prep)

libsepol.spec

@@ -48,7 +48,7 @@ The libsepol-static package contains the static libraries and header files
 needed for developing applications that manipulate binary policies. 
 
 %prep
-%autosetup -S git -p 1 -n libsepol-2.5
+%autosetup -p 1 -n libsepol-2.5
 
 # sparc64 is an -fPIC arch, so we need to fix it here
 %ifarch sparc64