Revert "jam: Fix bootstrap via absolutes in LD_LIBRARY_PATH"

This reverts commit 030d0eb58f.

It is absolutely not correct to assume PWD is the generated dir;
it may also be the repository root.

Fixes jam putting some build artifacts in the source tree.

build/jam/RepositoryRules

@@ -379,9 +379,9 @@ TREE_PATH="$(HAIKU_REPOSITORY_TREE_PATH)"
 TARGET_ARCHITECTURE="$(HAIKU_PACKAGING_ARCH)"
 
 DOWNLOAD_IN_PORT_DIRECTORY="yes"
-PACKAGE_COMMAND="$(PWD)/$(2[1])"
-MIMESET_COMMAND="$(PWD)/$(2[2])"
-SYSTEM_MIME_DB="$(PWD)/$(2[3])"
+PACKAGE_COMMAND="$(2[1])"
+MIMESET_COMMAND="$(2[2])"
+SYSTEM_MIME_DB="$(2[3])"
 LICENSES_DIRECTORY="$(HAIKU_ABSOLUTE_TOP)/data/system/data/licenses"
 OUTPUT_DIRECTORY="$(HAIKU_REPOSITORY_BUILD_DIRECTORY)"
 EOF