Fix Minor Psionics Bugs (#2190)

# Description

Fixes two bugs with Psionics, namely that the "Roller Exempt" psionic
variants were infact still able to roll new powers. Now the Roller
Exemption cuts them off completely from generating Potentia. I'll
probably revisit this exit at a later date if I come up with some
alternative uses for Potentia.

I also fixed a bug where probers would lock glimmer into one place,
rather than cause glimmer to steadily increase towards a given
equilibrium point(vs. the current linear decay rate).

# Changelog

🆑
- fix: Fixed a bug where Probers were locking glimmer at a set number.
- fix: Fixed a bug where Elementalists could still roll for new powers.

(cherry picked from commit 559c04fb5b55f65f0db34833282b4e92b801dc49)

Content.Server/Psionics/PsionicsSystem.cs

@@ -263,7 +263,7 @@ public sealed class PsionicsSystem : EntitySystem
     public void RollPsionics(EntityUid uid, PsionicComponent component, bool applyGlimmer = true, float rollEventMultiplier = 1f)
     {
         if (!_cfg.GetCVar(CCVars.PsionicRollsEnabled)
-            || !component.Removable)
+            || !component.Roller)
             return;
 
         // Calculate the initial odds based on the innate potential

Content.Shared/Psionics/Glimmer/GlimmerSystem.cs

@@ -118,10 +118,8 @@ public sealed class GlimmerSystem : EntitySystem
         if (!_enabled || delta == 0)
             return;
 
-        var x = GlimmerInput;
-
         GlimmerInput += delta;
-        GlimmerOutput = 2000 / (1 + Math.Pow(Math.E, -0.0022 * x)) - 1000;
+        GlimmerOutput = 2000 / (1 + Math.Pow(Math.E, -0.0022 * GlimmerInput)) - 1000;
     }
 
     /// <summary>
@@ -134,10 +132,8 @@ public sealed class GlimmerSystem : EntitySystem
         if (!_enabled || delta == 0)
             return;
 
-        var y = GlimmerOutput;
-
         GlimmerOutput += delta;
-        GlimmerInput = Math.Log((y + 1000) / (1000 - y)) / 0.0022;
+        GlimmerInput = Math.Log((GlimmerOutput + 1000) / (1000 - GlimmerOutput)) / 0.0022;
     }
 
     /// <summary>
@@ -150,10 +146,8 @@ public sealed class GlimmerSystem : EntitySystem
         if (!_enabled || set == 0)
             return;
 
-        var y = GlimmerOutput;
-
         GlimmerOutput = Math.Clamp(set, 0, 999.999);
-        GlimmerInput = Math.Log((y + 1000) / (1000 - y)) / 0.0022;
+        GlimmerInput = Math.Log((GlimmerOutput + 1000) / (1000 - GlimmerOutput)) / 0.0022;
     }
 
     /// <summary>
@@ -166,7 +160,6 @@ public sealed class GlimmerSystem : EntitySystem
         if (!_enabled || set < 0)
             return;
 
-
         GlimmerInput = set;
         GlimmerOutput = 2000 / (1 + Math.Pow(Math.E, -.0022 * set)) - 1000;
     }