Fix llvm-x86_64-debian-dylib buildbot

This was broken by 91a384621e5b762d9c173ffd247cfeadd5f436a2.

(cherry picked from commit ff4d6c64ee4269e4a9b67a4dae7e0b82ae1c3419)
diff --git a/llvm/test/lit.cfg.py b/llvm/test/lit.cfg.py
index c6f9ee8..74e7769 100644
--- a/llvm/test/lit.cfg.py
+++ b/llvm/test/lit.cfg.py
@@ -414,10 +414,11 @@
     config.available_features.add("llvm-dylib")
     config.substitutions.append(
         (
+            # libLLVM.so.19.0git
             "%llvmdylib",
-            "{}/libLLVM-{}{}".format(
-                config.llvm_shlib_dir, config.llvm_dylib_version, config.llvm_shlib_ext
-            ),
+            "{}/libLLVM{}.{}".format(
+                config.llvm_shlib_dir, config.llvm_shlib_ext, config.llvm_dylib_version
+            )
         )
     )
 
diff --git a/llvm/test/lit.site.cfg.py.in b/llvm/test/lit.site.cfg.py.in
index 1138b2c..b6f255d 100644
--- a/llvm/test/lit.site.cfg.py.in
+++ b/llvm/test/lit.site.cfg.py.in
@@ -44,7 +44,7 @@
 config.enable_threads = @LLVM_ENABLE_THREADS@
 config.build_shared_libs = @BUILD_SHARED_LIBS@
 config.link_llvm_dylib = @LLVM_LINK_LLVM_DYLIB@
-config.llvm_dylib_version = "@LLVM_VERSION_MAJOR@@LLVM_VERSION_SUFFIX@"
+config.llvm_dylib_version = "@LLVM_VERSION_MAJOR@.@LLVM_VERSION_MINOR@@LLVM_VERSION_SUFFIX@"
 config.llvm_host_triple = '@LLVM_HOST_TRIPLE@'
 config.host_arch = "@HOST_ARCH@"
 config.have_opt_viewer_modules = @LLVM_HAVE_OPT_VIEWER_MODULES@