remove unnecessary type conversions

Author: Achille Roussel

cpu/arm/arm.go

@@ -76,5 +76,5 @@ func ABI() CPU {
 	cpu.set(SHA1, ARM.HasSHA1)
 	cpu.set(SHA2, ARM.HasSHA2)
 	cpu.set(CRC32, ARM.HasCRC32)
-	return CPU(cpu)
+	return cpu
 }

cpu/arm64/arm64.go

@@ -70,5 +70,5 @@ func ABI() CPU {
 	cpu.set(SHA512, ARM64.HasSHA512)
 	cpu.set(SVE, ARM64.HasSVE)
 	cpu.set(ASIMDFHM, ARM64.HasASIMDFHM)
-	return CPU(cpu)
+	return cpu
 }

cpu/x86/x86.go

@@ -72,5 +72,5 @@ func ABI() CPU {
 	cpu.set(AVX512VP2INTERSECT, false) // TODO: add upstream support in golang.org/x/sys/cpu?
 	cpu.set(AVX512VPOPCNTDQ, X86.HasAVX512VPOPCNTDQ)
 	cpu.set(CMOV, true) // TODO: golang.org/x/sys/cpu assumes all CPUs have CMOV?
-	return CPU(cpu)
+	return cpu
 }