Bazel: Fix lint warning flagged by buildifier

This change is fixing confusing name warning: [1].

  ./org.eclipse.jgit.test/tests.bzl:12: confusing-name:
  Never use 'l', 'I', or 'O' as names (they're too easily confused
  with 'I', 'l', or '0').

And is also fixing: "All calls to rules or macros should pass arguments
by keyword position argument" warning: [2].

  ./org.eclipse.jgit.test/BUILD:42: positional-args: All calls to rules
  or macros should pass arguments by keyword (arg_name=value) syntax.

[1] https://github.com/bazelbuild/buildtools/blob/master/WARNINGS.md#confusing-name
[2] https://github.com/bazelbuild/buildtools/blob/master/WARNINGS.md#positional-args

Change-Id: If5c28ec8a1ddc1d1b1035bd07b838a2a564aea4f
Signed-off-by: David Ostrovsky <david@ostrovsky.org>

org.eclipse.jgit.test/BUILD

@@ -30,7 +30,7 @@ DATA = [
     PKG + "lib/sorttest.gitindex.dat",
 ]
 
-tests(glob(
+tests(tests = glob(
     ["tst/**/*.java"],
     exclude = HELPERS + DATA,
 ))

org.eclipse.jgit.test/tests.bzl

@@ -8,14 +8,14 @@ def tests(tests):
         name = src[len("tst/"):len(src) - len(".java")].replace("/", "_")
         labels = []
         if name.startswith("org_eclipse_jgit_"):
-            l = name[len("org.eclipse.jgit_"):]
-            if l.startswith("internal_storage_"):
-                l = l[len("internal.storage_"):]
-            i = l.find("_")
-            if i > 0:
-                labels.append(l[:i])
+            package = name[len("org.eclipse.jgit_"):]
+            if package.startswith("internal_storage_"):
+                package = package[len("internal.storage_"):]
+            index = package.find("_")
+            if index > 0:
+                labels.append(package[:index])
             else:
-                labels.append(i)
+                labels.append(index)
         if "lib" not in labels:
             labels.append("lib")