[ELF] maybeReportUndefined: move sym.isUndefined() check to the calle…

…r. NFC

Avoid a function call in the majority of cases.

lld/ELF/Relocations.cpp

@@ -739,8 +739,6 @@ template <class ELFT> void elf::reportUndefinedSymbols() {
 // Returns true if the undefined symbol will produce an error message.
 static bool maybeReportUndefined(Symbol &sym, InputSectionBase &sec,
                                  uint64_t offset) {
-  if (!sym.isUndefined())
-    return false;
   // If versioned, issue an error (even if the symbol is weak) because we don't
   // know the defining filename which is required to construct a Verneed entry.
   if (*sym.getVersionSuffix() == '@') {
@@ -1327,7 +1325,8 @@ static void scanReloc(InputSectionBase &sec, OffsetGetter &getOffset, RelTy *&i,
 
   // Error if the target symbol is undefined. Symbol index 0 may be used by
   // marker relocations, e.g. R_*_NONE and R_ARM_V4BX. Don't error on them.
-  if (symIndex != 0 && maybeReportUndefined(sym, sec, rel.r_offset))
+  if (sym.isUndefined() && symIndex != 0 &&
+      maybeReportUndefined(sym, sec, rel.r_offset))
     return;
 
   const uint8_t *relocatedAddr = sec.data().begin() + rel.r_offset;