FFI processor example uses incorrect glibc SONAME (libc.6.so vs libc.so.6)

[JakeSCahill]

Description

The FFI processor's example uses incorrect glibc naming:

• Summary says: "loading libc.so"
• library_path uses: libc.6.so

The correct Linux glibc SONAME is libc.so.6, not libc.6.so.

Location

The example appears in the FFI processor definition (likely in internal/impl/ffi/processor.go or similar).

Current Example

pipeline:
  processors:
    - ffi:
        library_path: libc.6.so  # Should be libc.so.6
        function_name: memcmp
        args_mapping: 'root = ["foo", "bar", 3]'
        signature:
          return:
            type: int32
          parameters:
            - type: byte*
            - type: byte*
            - type: int64

Expected

library_path: libc.so.6

And update the summary text to use libc.so.6 consistently.

Impact

This affects the auto-generated documentation at https://docs.redpanda.com/redpanda-connect/components/processors/ffi/

Found via CodeRabbit review on rp-connect-docs#435.