Resolved all outstanding warnings.

src/lib-sieve/sieve-ast.c

src/lib-sieve/sieve-ast.h

src/lib-sieve/sieve-binary.c

src/lib-sieve/sieve-binary.h

src/lib-sieve/sieve-code.c

src/lib-sieve/sieve-code.h

src/lib-sieve/sieve-commands.c

src/lib-sieve/sieve-commands.h

src/lib-sieve/sieve-comparators.c

src/lib-sieve/sieve-comparators.h

src/lib-sieve/sieve-generator.c

src/lib-sieve/sieve-generator.h

src/lib-sieve/sieve-interpreter.c

src/lib-sieve/sieve-interpreter.h

src/lib-sieve/sieve-lexer.c

src/lib-sieve/sieve-lexer.h

src/lib-sieve/sieve-result.c

src/lib-sieve/sieve-result.h

src/lib-sieve/sieve-script.c

src/lib-sieve/sieve-script.h