scripted-diff: Rename FatalError to FatalErrorf

This is done in preparation for the next commit where a new FatalError
function is introduced. FatalErrorf follows common convention to append
'f' for functions accepting format arguments.

-BEGIN VERIFY SCRIPT-
sed -i 's/FatalError/FatalErrorf/g' $( git grep -l 'FatalError')
-END VERIFY SCRIPT-

test/lint/run-lint-format-strings.py

@@ -14,7 +14,7 @@ import sys
 
 FALSE_POSITIVES = [
     ("src/dbwrapper.cpp", "vsnprintf(p, limit - p, format, backup_ap)"),
-    ("src/index/base.cpp", "FatalError(const char* fmt, const Args&... args)"),
+    ("src/index/base.cpp", "FatalErrorf(const char* fmt, const Args&... args)"),
     ("src/netbase.cpp", "LogConnectFailure(bool manual_connection, const char* fmt, const Args&... args)"),
     ("src/clientversion.cpp", "strprintf(_(COPYRIGHT_HOLDERS).translated, COPYRIGHT_HOLDERS_SUBSTITUTION)"),
     ("src/test/translation_tests.cpp", "strprintf(format, arg)"),