[libc][NFC] reuse variable in printf string conv

[michaelrj]

Summary

The amount of spaces to pad with is stored in the variable
padding_spaces, previously the actual write calls used the same formula
to calculate the value. This simplifies and clarifies the values by just
reusing the variable.

libc/src/stdio/printf_core/char_converter.h

LIBC_INLINE int convert_char(Writer *writer, const FormatSection &to_conv) {
   constexpr int string_len = 1;
 
   size_t padding_spaces =
       to_conv.min_width > string_len ? to_conv.min_width - string_len : 0;
 
   // If the padding is on the left side, write the spaces first.
   if (padding_spaces > 0 &&
       (to_conv.flags & FormatFlags::LEFT_JUSTIFIED) == 0) {
-    RET_IF_RESULT_NEGATIVE(writer->write(' ', to_conv.min_width - string_len));
+    RET_IF_RESULT_NEGATIVE(writer->write(' ', padding_spaces));
   }
 
   RET_IF_RESULT_NEGATIVE(writer->write(c));
 
   // If the padding is on the right side, write the spaces last.
   if (padding_spaces > 0 &&
       (to_conv.flags & FormatFlags::LEFT_JUSTIFIED) != 0) {
-    RET_IF_RESULT_NEGATIVE(writer->write(' ', to_conv.min_width - string_len));
+    RET_IF_RESULT_NEGATIVE(writer->write(' ', padding_spaces));
   }
 
   return WRITE_OK;
 }
 
 } // namespace printf_core
 } // namespace __llvm_libc
 
 #endif // LLVM_LIBC_SRC_STDIO_PRINTF_CORE_CHAR_CONVERTER_H

libc/src/stdio/printf_core/string_converter.h

LIBC_INLINE int convert_string(Writer *writer, const FormatSection &to_conv) {
 
   size_t padding_spaces = to_conv.min_width > static_cast<int>(string_len)
                               ? to_conv.min_width - string_len
                               : 0;
 
   // If the padding is on the left side, write the spaces first.
   if (padding_spaces > 0 &&
       (to_conv.flags & FormatFlags::LEFT_JUSTIFIED) == 0) {
-    RET_IF_RESULT_NEGATIVE(writer->write(' ', to_conv.min_width - string_len));
+    RET_IF_RESULT_NEGATIVE(writer->write(' ', padding_spaces));
   }
 
   RET_IF_RESULT_NEGATIVE(writer->write(
       {reinterpret_cast<const char *>(to_conv.conv_val_ptr), string_len}));
 
   // If the padding is on the right side, write the spaces last.
   if (padding_spaces > 0 &&
       (to_conv.flags & FormatFlags::LEFT_JUSTIFIED) != 0) {
-    RET_IF_RESULT_NEGATIVE(writer->write(' ', to_conv.min_width - string_len));
+    RET_IF_RESULT_NEGATIVE(writer->write(' ', padding_spaces));
   }
   return WRITE_OK;
 }
 
 } // namespace printf_core
 } // namespace __llvm_libc
 
 #endif // LLVM_LIBC_SRC_STDIO_PRINTF_CORE_STRING_CONVERTER_H