perf expr: Fix missing check for return value of hashmap__new()

The hashmap__new() function may return ERR_PTR(-ENOMEM) when malloc()
fails, add IS_ERR() checking for ctx->ids.
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20211212062504.25841-1-linmq006@gmail.com
[ s/kfree()/free()/ and add missing linux/err.h include ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/expr.c

@@ -12,6 +12,7 @@
 #include "expr-bison.h"
 #include "expr-flex.h"
 #include "smt.h"
+#include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/zalloc.h>
 #include <ctype.h>
@@ -299,6 +300,10 @@ struct expr_parse_ctx *expr__ctx_new(void)
 		return NULL;
 
 	ctx->ids = hashmap__new(key_hash, key_equal, NULL);
+	if (IS_ERR(ctx->ids)) {
+		free(ctx);
+		return NULL;
+	}
 	ctx->runtime = 0;
 
 	return ctx;