perf tests record+zstd_comp_decomp: Fix the shellcheck warnings about word splitting/quoting

Running shellcheck on record+zstd_comp_decomp.sh testcases
throws below warning:

   In tests/shell/record+zstd_comp_decomp.sh line 16:
       	   $perf_tool record -o $trace_file $gflag -z -F 5000 -- \
                                ^---------^ SC2086 (info): Double quote to prevent globbing and word splitting.

   Did you mean:
     	   $perf_tool record -o "$trace_file" $gflag -z -F 5000 -- \

   In tests/shell/record+zstd_comp_decomp.sh line 22:
	   $perf_tool report -i $trace_file --header --stats | \
                                ^---------^ SC2086 (info): Double quote to prevent globbing and word splitting.

Added double quote around file names to fix these
shellcheck reported issues.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230709182800.53002-23-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>