drm/xe: Fix and re-enable xe_print_blob_ascii85()

drm/xe: Fix and re-enable xe_print_blob_ascii85()

Commit 70fb86a85dc9 ("drm/xe: Revert some changes that break a mesa
debug tool") partially reverted some changes to workaround breakage
caused to mesa tools. However, in doing so it also broke fetching the
GuC log via debugfs since xe_print_blob_ascii85() simply bails out.

The fix is to avoid the extra newlines: the devcoredump interface is
line-oriented and adding random newlines in the middle breaks it. If a
tool is able to parse it by looking at the data and checking for chars
that are out of the ascii85 space, it can still do so. A format change
that breaks the line-oriented output on devcoredump however needs better
coordination with existing tools.

v2: Add suffix description comment
v3: Reword explanation of xe_print_blob_ascii85() calling drm_puts()
    in a loop

Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Julia Filipchuk <julia.filipchuk@intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: stable@vger.kernel.org
Fixes: 70fb86a85dc9 ("drm/xe: Revert some changes that break a mesa debug tool")
Fixes: ec1455ce7e35 ("drm/xe/devcoredump: Add ASCII85 dump helper function")
Link: https://patchwork.freedesktop.org/patch/msgid/20250123202307.95103-2-jose.souza@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>