perf expr: Add missing headers noticed when building with NO_LIBBPF=1

These will break the build as soon as we stop disabling all warnings
when building flex and bison generated files, so add them before we do
that to keep the tree bisectable.

Noticed when building on centos:7 with NO_LIBBPF=1:

  util/expr.c: In function 'key_equal':
  util/expr.c:29:2: error: implicit declaration of function 'strcmp' [-Werror=implicit-function-declaration]
    return !strcmp((const char *)key1, (const char *)key2);
    ^
  util/expr.c: In function 'expr__add_id':
  util/expr.c:40:3: error: implicit declaration of function 'malloc' [-Werror=implicit-function-declaration]
     val_ptr = malloc(sizeof(double));
     ^
  util/expr.c:40:13: error: incompatible implicit declaration of built-in function 'malloc' [-Werror]
     val_ptr = malloc(sizeof(double));
               ^
  util/expr.c:42:12: error: 'ENOMEM' undeclared (first use in this function)
      return -ENOMEM;
              ^
Signed-off-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Jin Yao <[email protected]>
Cc: John Garry <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions