[committed][gdb/testsuite] Fix PATH warning in gdb.rust/traits.exp

[Tom de Vries <tdevries@suse.de>]

Hi,

When running the rust test-cases with release 1.36.0 and LLVM version 7.0, I
run into:
...
(gdb) UNTESTED: gdb.rust/traits.exp: could not read \
  outputs/gdb.rust/traits/traits with readelf
PATH: gdb.rust/traits.exp: could not read \
  outputs/gdb.rust/traits/traits with readelf
...

Fix the PATH warning by printing [file tail $binfile] instead $binfile.

Tested on x86_64-linux.

Committed to trunk.

Thanks,
- Tom

[gdb/testsuite] Fix PATH warning in gdb.rust/traits.exp

gdb/testsuite/ChangeLog:

2020-09-14  Tom de Vries  <tdevries@suse.de>

	* gdb.rust/traits.exp: Fix PATH warning.

---
 gdb/testsuite/gdb.rust/traits.exp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/testsuite/gdb.rust/traits.exp b/gdb/testsuite/gdb.rust/traits.exp
index ac2b4506f3..41e58e1fef 100644
--- a/gdb/testsuite/gdb.rust/traits.exp
+++ b/gdb/testsuite/gdb.rust/traits.exp
@@ -28,7 +28,7 @@ if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug rust}]} {
 set readelf_program [gdb_find_readelf]
 set result [catch "exec $readelf_program --debug-dump=info $binfile" output]
 if {$result != 0} {
-    untested "could not read ${binfile} with readelf"
+    untested "could not read [file tail ${binfile}] with readelf"
     return
 }