[PATCH v4l-utils v2] v4l-utils: include cstdlib for std::exit

[Nick Desaulniers <ndesaulniers@google.com>]

libc++ recently trimmed their list of transitive includes. Include
<cstdlib> for the declaration of std::exit to avoid compile time errors
against newer versions of libc++.

Fixes:

    v4l-utils/utils/v4l2-compliance/v4l2-test-input-output.cpp:53:11:
    error: no member named 'exit' in namespace 'std'; did you mean simply
    'exit'?
       53 |                         return fail("couldn't get freq band\n");
          |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    v4l-utils/utils/v4l2-compliance/v4l2-compliance.h:286:3: note:
    expanded from macro 'fail'
      286 |                 std::exit(EXIT_FAILURE);
          |                 ^    ~~~~
    bionic/libc/include/stdlib.h:55:17: note: 'exit' declared here
       55 | __noreturn void exit(int __status);
          |                 ^

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
Changes in v2:
- Also fixup v4l2-ctl.h; many .cpp files including it refer to
  std::exit, not exit.
- Link to v1: https://lore.kernel.org/r/20260717-libcpp_transitive-v1-1-3af91860affe@google.com
---
 utils/v4l2-compliance/v4l2-compliance.h | 1 +
 utils/v4l2-ctl/v4l2-ctl.h               | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/utils/v4l2-compliance/v4l2-compliance.h b/utils/v4l2-compliance/v4l2-compliance.h
index b43c5817..7ca4744e 100644
--- a/utils/v4l2-compliance/v4l2-compliance.h
+++ b/utils/v4l2-compliance/v4l2-compliance.h
@@ -25,6 +25,7 @@
 #include <set>
 #include <string>
 #include <cstdint>
+#include <cstdlib>
 
 #include <linux/videodev2.h>
 #include <linux/v4l2-subdev.h>
diff --git a/utils/v4l2-ctl/v4l2-ctl.h b/utils/v4l2-ctl/v4l2-ctl.h
index ae6f43f3..483b2c36 100644
--- a/utils/v4l2-ctl/v4l2-ctl.h
+++ b/utils/v4l2-ctl/v4l2-ctl.h
@@ -2,9 +2,9 @@
 #define _V4L2_CTL_H
 
 #include <cstdint>
+#include <cstdlib>
 #include <linux/videodev2.h>
 #include <linux/v4l2-subdev.h>
-#include <stdlib.h>
 #include <v4l-getsubopt.h>
 
 #include <v4l2-info.h>

---
base-commit: b32589c514810daacc05a2015d205b997cd11970
change-id: 20260717-libcpp_transitive-0c6a9e39e5f9

Best regards,
-- 
Nick Desaulniers <ndesaulniers@google.com>