Fix shellcheck warning in fuzz_static_testcases.sh

changes/ticket29059

@@ -0,0 +1,3 @@
+  o Code simplification and refactoring (shell scripts):
+    - Fix shellcheck warnings in fuzz_static_testcases.sh. Resolves ticket
+      29059.

src/test/fuzz_static_testcases.sh

@@ -14,7 +14,7 @@ fi
 
 
 for fuzzer in "${builddir:-.}"/src/test/fuzz/fuzz-* ; do
-    f=`basename $fuzzer`
+    f=$(basename "$fuzzer")
     case="${f#fuzz-}"
     if [ -d "${TOR_FUZZ_CORPORA}/${case}" ]; then
         echo "Running tests for ${case}"