checkasm: Remove unnecessary const on scalar parameters

The ffmpeg coding style doesn't usually use const on scalar
parameters (or on the pointer values - as opposed to the type
that is pointed to, where it has a semantic meaning), contrary
to the dav1d coding style (where this was imported from).

This avoids warnings about differences in the type signatures
between declaration and definition of this function, with older
versions of MSVC.

The issue was observed with one version of MSVC 2017,
19.16.27024.1, with warnings like these:

    src/tests/checkasm/checkasm.c(969): warning C4028: formal parameter 3 different from declaration

The warning itself is bogus as the const here is harmless, and
newer versions of MSVC no longer warn about this.

Signed-off-by: Martin Storsjö <martin@martin.st>

tests/checkasm/checkasm.c

@@ -933,10 +933,10 @@ void checkasm_report(const char *name, ...)
 }
 
 #define DEF_CHECKASM_CHECK_FUNC(type, fmt) \
-int checkasm_check_##type(const char *const file, const int line, \
+int checkasm_check_##type(const char *file, int line, \
                           const type *buf1, ptrdiff_t stride1, \
                           const type *buf2, ptrdiff_t stride2, \
-                          const int w, int h, const char *const name) \
+                          int w, int h, const char *name) \
 { \
     int y = 0; \
     stride1 /= sizeof(*buf1); \

tests/checkasm/checkasm.h

@@ -308,10 +308,10 @@ typedef struct CheckasmPerf {
 #endif
 
 #define DECL_CHECKASM_CHECK_FUNC(type) \
-int checkasm_check_##type(const char *const file, const int line, \
-                          const type *const buf1, const ptrdiff_t stride1, \
-                          const type *const buf2, const ptrdiff_t stride2, \
-                          const int w, const int h, const char *const name)
+int checkasm_check_##type(const char *file, int line, \
+                          const type *buf1, ptrdiff_t stride1, \
+                          const type *buf2, ptrdiff_t stride2, \
+                          int w, int h, const char *name)
 
 DECL_CHECKASM_CHECK_FUNC(uint8_t);
 DECL_CHECKASM_CHECK_FUNC(uint16_t);