tests/shell: Fix shellcheck warnings for SC2153 in multiple scripts

Running shellcheck on some of the shell scripts, throws
below warning on shellcheck v0.6. Example:

In tests/shell/coresight/asm_pure_loop.sh line 14:
DATA="$DATD/perf-$TEST-$DATV.data"
^---^ SC2153: Possible misspelling: DATD may not be assigned, but DATA is.

Here, DATD is exported from "lib/coresight.sh" and this
warning can be ignored. Use "shellcheck disable=" to ignore
this check.

Signed-off-by: Athira Rajeev <[e-mail]>
Tested-by: Ian Rogers <[e-mail]>
Reviewed-by: Kajol Jain <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Namhyung Kim <[e-mail]>

tools/perf/tests/shell/coresight/asm_pure_loop.sh

···
 
 ARGS=""
 DATV="out"
+# shellcheck disable=SC2153
 DATA="$DATD/perf-$TEST-$DATV.data"
 
 perf record $PERFRECOPT -o "$DATA" "$BIN" $ARGS

tools/perf/tests/shell/coresight/memcpy_thread_16k_10.sh

···
 
 ARGS="16 10 1"
 DATV="16k_10"
+# shellcheck disable=SC2153
 DATA="$DATD/perf-$TEST-$DATV.data"
 
 perf record $PERFRECOPT -o "$DATA" "$BIN" $ARGS

tools/perf/tests/shell/coresight/thread_loop_check_tid_10.sh

···
 
 ARGS="10 1"
 DATV="check-tid-10th"
+# shellcheck disable=SC2153
 DATA="$DATD/perf-$TEST-$DATV.data"
 STDO="$DATD/perf-$TEST-$DATV.stdout"
 

tools/perf/tests/shell/coresight/thread_loop_check_tid_2.sh

···
 
 ARGS="2 20"
 DATV="check-tid-2th"
+# shellcheck disable=SC2153
 DATA="$DATD/perf-$TEST-$DATV.data"
 STDO="$DATD/perf-$TEST-$DATV.stdout"
 

tools/perf/tests/shell/coresight/unroll_loop_thread_10.sh

···
 
 ARGS="10"
 DATV="10"
+# shellcheck disable=SC2153
 DATA="$DATD/perf-$TEST-$DATV.data"
 
 perf record $PERFRECOPT -o "$DATA" "$BIN" $ARGS