capi: Don't use vmlinux in symbolize_in_kernel() test

The symbolize_in_kernel() test may inadvertently use a vmlinux file that
could be present on the system and that could lead to a wrong
symbolization. Given that the test is only meant to work with kallsyms
image, disable usage of vmlinux altogether to prevent any interference
with system data.

Signed-off-by: Daniel Müller <[email protected]>

capi/src/symbolize.rs

@@ -1986,6 +1986,7 @@ mod tests {
         let path_c = CString::new(path.to_str().unwrap()).unwrap();
         let src = blaze_symbolize_src_kernel {
             kallsyms: path_c.as_ptr(),
+            vmlinux: b"\0" as *const _ as *const c_char,
             ..Default::default()
         };