Simplify code slightly in roundmultiple #138

Job	Run time
MSIS code validation (ubuntu-latest)	8s
MSIS code validation (macos-latest)	10s
XML validation	14s
C/C++ build (MSVC) (ON)	6m 39s
C/C++ build (MinGW) (ON)	3m 11s
C/C++ build (MacOSX) (macos-12, 3.8)	4m 30s
C/C++ build (MSVC) (OFF)	4m 43s
C/C++ build (Linux) (ubuntu-22.04, ON, ON, OFF, ON)	3m 58s
C/C++ build (MinGW) (OFF)	4m 13s
C/C++ build (MacOSX) (macos-14, 3.10)	2m 20s
C/C++ build (Linux) (ubuntu-22.04, ON, OFF, OFF, ON)	3m 54s
C/C++ build (Linux) (ubuntu-22.04, OFF, ON, OFF, ON)	3m 58s
C/C++ build (Linux) (ubuntu-22.04, OFF, OFF, OFF, ON)	4m 18s
C/C++ build (Linux) (ubuntu-20.04, OFF, OFF, ON, OFF)	5m 32s
Build Python Module from Source	0s
Code coverage	2m 10s
Matlab S-Function (macos-12)	7m 23s
Matlab S-Function (ubuntu-22.04)	2m 44s
Build Python wheels	0s
Matlab S-Function (windows-latest)	6m 6s
Build Windows installer	0s
Deploy Rolling Release	0s
Deploy Stable Release	0s
Deploy Documentation	0s
	1h 6m 11s

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