.github/workflows: Set DID_UNSHARE programmatically instead of explicitly

Instead of having to define the DID_UNSHARE value explicitly as part of the test
matrix, set the environment variable programmatically based on the kernel
version. This removes the need for a lot of copy-paste to accommodate the two
old kernel versions, now that we also have clang versions as part of the test
matrix.

Signed-off-by: Toke Høiland-Jørgensen <[email protected]>

Author: tohojo

.github/workflows/selftests.yml

@@ -16,27 +16,23 @@ jobs:
           - "6.6.14-200.fc39"
           - "6.1.9-200.fc37"
           - "5.16.8-200.fc35"
-        DID_UNSHARE:
-          - 0
+          - "5.11.0-156.fc34"
+          - "5.6.19-300.fc32"
         CLANG_VERSION:
           - 16
           - 17
           - 18
           - 19
-        include:
-         - KERNEL_VERSION: "5.11.0-156.fc34"
-           DID_UNSHARE: 1
-         - KERNEL_VERSION: "5.6.19-300.fc32"
-           DID_UNSHARE: 1
       fail-fast: false
 
     env:
       KERNEL_VERSION: ${{ matrix.KERNEL_VERSION }}
-      DID_UNSHARE: ${{ matrix.DID_UNSHARE }}
       CLANG_VERSION: ${{ matrix.CLANG_VERSION }}
       CLANG: clang-${{ matrix.CLANG_VERSION }}
       LLC: llc-${{ matrix.CLANG_VERSION }}
       LLVM_STRIP: llvm-strip-${{ matrix.CLANG_VERSION }}
+      # can't use unshare on old kernels
+      DID_UNSHARE: ${{ (startsWith(matrix.KERNEL_VERSION, '5.6') || startsWith(matrix.KERNEL_VERSION, '5.11')) && 1 || 0 }}
 
     steps:
       - name: Check out repository code