style: add missing braces to strdup NULL checks

[cfsmp3]

Summary

• Add { } braces to all 11 bare if blocks introduced by [FIX] Check strdup() return values in lib_ccx; remove strdup of string literals #2213
• Covers: ccx_common_common.c, ccx_encoders_common.c, ccx_encoders_helpers.c, configuration.c, hardsubx.c, hardsubx_decoder.c, ocr.c, output.c

Test plan

• Builds clean, no warnings
• Output byte-identical to master on MPG and DVR-MS samples
• Valgrind: 0 errors

🤖 Generated with Claude Code