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 <atrajeev@linux.vnet.ibm.com>
Tested-by: Ian Rogers <irogers@google.com>
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Cc: maddy@linux.ibm.com
Cc: disgoel@linux.vnet.ibm.com
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230907171540.36736-4-atrajeev@linux.vnet.ibm.comSigned-off-by: Namhyung Kim <namhyung@kernel.org>

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

@@ -11,6 +11,7 @@ TEST="asm_pure_loop"
 
 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

@@ -11,6 +11,7 @@ TEST="memcpy_thread"
 
 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

@@ -11,6 +11,7 @@ TEST="thread_loop"
 
 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

@@ -11,6 +11,7 @@ TEST="thread_loop"
 
 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

@@ -11,6 +11,7 @@ TEST="unroll_loop_thread"
 
 ARGS="10"
 DATV="10"
+# shellcheck disable=SC2153
 DATA="$DATD/perf-$TEST-$DATV.data"
 
 perf record $PERFRECOPT -o "$DATA" "$BIN" $ARGS