Rewrite jamMask expression to use new jamMaskShift (no functional change)

Signed-off-by: Nicolas Brunie <nibrunie@gmail.com>

Author: nibrunie

src/unpriv/rvbna.adoc

@@ -208,7 +208,8 @@ BulkNormalizedDotProduct(A[n], B[n]) {
     let resExp = accumulator == 0 ? 0 : ((maxExp + o + 1 - lzc) - prodOpBias + res_bias)
     let unroundedSig = (accAbs << lzc) >> (g + o + 1)
     let rawJamMask = (1 << (g + o + 1)) - 1
-    let jamMask = (rawJamMask >> (lzc > (g + o + 1) ? 0 : (g + o + 1 - lzc)))
+    let jamMaskShift = (lzc > (g + o + 1) ? 0 : (g + o + 1 - lzc))
+    let jamMask = rawJamMask >> jamMaskShift
 
     let jamSig = ((accAbs << lzc) & jamMask) != 0
     let roundedSig = unroundedSig | (jamSig ? 1 : 0)